C Programming Absolute Beginner's Guide (3rd Edition)

values, no matter how large or small the values stored there are. On any given day, a

large post office box might get much less mail than a smaller one. The contents of the

box don’t affect what the box is capable of holding. The size of C’s number storage is

affected not by the value of the number, but by the type of the number.

Different C compilers use different amounts of storage for integers and floating-point values. As you
will learn later, there are ways of finding out exactly how much memory your C compiler uses for
each type of data.

Wrapping Things Up with Another Example Program

This chapter’s goal was to familiarize you with the “look and feel” of a C program, primarily the
main() function that includes executable C statements. As you saw, C is a free-form language that
isn’t picky about spacing. C is, however, picky about lowercase letters. C requires lowercase
spellings of all its commands and functions, such as printf().

At this point, don’t worry about the specifics of the code you see in this chapter. The rest of the book
explains all the details. But it is still a great idea to type and study as many programs as possible—
practice will increase your coding confidence! So here is a second program, one that uses the data
types you just covered:

Click here to view code image

/* A Program that Uses the Characters, Integers, and Floating-Point

Data Types */

#include <stdio.h>

main()

{

printf("I am learning the %c programming language\n", 'C');

printf("I have just completed Chapter %d\n", 2);

printf("I am %.1f percent ready to move on ", 99.9);

printf("to the next chapter!\n");

return 0;

}

This short program does nothing more than print three messages onscreen. Each message includes one
of the three data types mentioned in this chapter: a character (C), an integer ( 2 ), and a floating-point
number (99.9).

Note

On the first printf statement, the %c tells the program where to introduce the

character 'C'. It is %c as an abbreviation for character, not because the character is a

C. If you were learning the N programming language, you would still use %c to place

the 'N' character.

The main() function is the only function in the program written by the programmer. The left and
right braces ({ and }) always enclose the main() code, as well as any other function’s code that